1. Field of the Invention
This invention relates to a mudflap assembly wherein the mudflap mounting bracket is resiliently mounted to a seat for flexing action during operation of the vehicle.
2. State of the Prior Art
Mudguards or mudflaps are used primarily behind dual rear-wheeled truck and trailer vehicles. The mudflap support assemblies must have the ability to flex in forward and rear directions as well as in vertical directions. Some mudguard mounting structures comprise a single piece of spring-like bar stock bent in a shape for supporting the mudguards and for flexing in all directions. For example, see Betts, U.S. Pat. No. 2,970,849, issued Feb. 7, 1961, and Juergens, U.S. Pat. No. 3,782,757, issued Jan. 1, 1975.
Other mounting assemblies for mudflaps use a rigid hanger assembly and resiliently bias the hanger assembly to a seat which is attached to a vehicle. For example, see Prohl, et al, U.S. Pat. No. 3,401,953, issued Sept. 17, 1968. In such assemblies, provision must be made to permit the hanger assembly to flex with respect to the seat through an angle of substantially 360.degree. about the seat. In other words, the mounting must permit the hanger to flex forward, backward, up and down with respect to the seat. Further, means must be provided for restraining rotational movement of the hanger assembly with respect to the seat so that the mudflap always remains in its vertical orientation. If the hanger rotates so that the flap moves toward the wheels, the wheels may prematurely wear the mudflap away. If the hanger rotates in an opposite direction, the effectiveness of the mudflap may be diminished.
In the Prohl et al structure, the seat comprises a round plate and the hanger includes an elongated tube which fits over the round plate. A coil spring fits within the tube with one end of the coil spring being retained by a hook on the seat and the other end of the coil spring being retained midway in the elongated tube. In one embodiment, a retainer within the tube grips the end of the spring and restrains rotation of the spring with respect to the tube. In another embodiment, a special rigid link is connected to the inner end of the coil spring and a pin extends through a slot in the link and through the hollow tube to restrain rotation of the spring with respect to the tube.
The former spring restraint is fairly ineffective to prevent small deviations in alignment of the hanger assembly with respect to the seat. The latter spring restraint is also ineffective to prevent such small deviations because of the required tolerance between the hook on the rigid link and the hook on the metal plate. Further, the possibility exists that the hollow tube will not completely seat back over the round plate at the conclusion of any flexing cycle because of the apparent close fit of the hollow tube over the round plate.